| As a coal country,the production of fly ash has been highed,our country’s fly ash production of about 600 million tons in 2016.By the end of 2016,with the accumulation over the years,the amount of fly ash has reached 3 billion tons.Although there are many application areas of fly ash,but the amount of application is very limited.Take this into account that the application of fly ash,the mineralogical analysis and magnetic mineral sorting of fly ash were carried out and the content of mineral phases were measured,which provided the theoretical basis for the application of fly ash.The results show as the following:The average particle size of individual mineral in fly ash is 25.70μm of glass,35.9μm of quartz,19.8μm of mullite,17.1μm of magnetite,21.4μm of hematite and 18.5μm of f-Ca O.The content of minerals in fly ash is 53.99% of glass,25.53% of quartz,17.98% of mullite,1.72% of magnetite,0.2% of hematite and 0.15% of f-Ca O;The liberation degree of the magnetite monomer is 28.73%,the liberation degree of the hematite monomer is 15.48%,the liberation degree of the glass monomer is 57.65% and the glass in fly ash is mostly single or with the other minerals were two connected relationship exists;fly ash particle density distribution is mainly concentrated from 2.6g/cm3 to 3.2g/cm3.A new chemical phase analysis has been presented in which fly ash was dissolved by alkaline solution,acidic solution successively,after dissolubility of individual mineral in fly ash was acquired.Mullite,quartz,magnetite,hematite and unburn carbon grain in fly ash are inert mineral with alkaline solution or acidic solution.The glass and f-Ca O can form gel firstly activated in alkaline solution,then the gel was completely dissolved in acidic solution.The two mineral compositions disappeared after the dissolving process,and they are loss on dissolution.Glass content equals to the value minus f-Ca O content.Determination the content of magnetic minerals in fly ash by Rietveld full spectral fitting method.The content of magnetic minerals in raw materials of fly ash was 2.05%.When the fly ash was divided into different grain grades,the content of magnetic minerals increased with the increase of grain size,and the magnetic mineral content in +106μm grain size was 6.42%,is-30μm grain size of 11.46 times,3.13 times of the raw material.From the enrichment factor of magnetic minerals in each particle size,the magnetic minerals in fly ash are mainly enriched in the coarse grain grade,and the enrichment factor increases with the increase of grain size.Fly ash from the O-Sepa separator obtain coarse powder and fine powder two products.In this paper,three kinds of air flow were used for sorting,respectively Q1,Q2 and Q3.The three median separation diameters were 22 μm,30 μm and 35 μm,respectively,the effect of gas separation was characterized by Newtonian separation efficiency.The Newtonian separation efficiency of Q1 is 75.46%,Q2 is 80.35%,Q3 is 85.8%,Three kinds of air volume comparison,Q3 sorting effect is better.When the air intake volume is Q3,the content of magnetic minerals of coarse powder was 3.07%,the content of glass was 58.83%,less magnetic mineral content of fine powder was 0.23%,the content of glass was 57.22%,the content of magnetic minerals of coarse powder separation of products is 13.35 times than fine powder,fly ash by pneumatic separation,the magnetic minerals are enriched in coarse powder. |
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